Power decoupling attachment

ABSTRACT

An embodiment of the invention may include a method, and resulting structure, of forming a semiconductor structure. The method may include forming a component hole from a first surface to a second surface of a base layer. The method may include placing an electrical component in the component hole. The electrical component has a conductive structure on both ends of the electrical component. The electrical component is substantially parallel to the first surface. The method may include forming a laminate layer on the first surface of the base layer, the second surface of the base layer, and between the base layer and the electrical component. The method may include creating a pair of via holes, where the pair of holes align with the conductive structures on both ends of the electrical component. The method may include forming a conductive via in the pair of via holes.

BACKGROUND

The present invention relates to semiconductor manufacturing, and morespecifically, to fabrication of interposers.

An interposer is an electrical interface routing between one socket orconnection to another. The purpose of an interposer is to spread aconnection to a wider pitch or to reroute a connection to a differentconnection.

In microelectronics, a three-dimensional integrated circuit (3D IC) isan integrated circuit manufactured by stacking silicon wafers and/ordies and interconnecting them vertically using through-silicon vias(TSVs) so that they behave as a single device to achieve performanceimprovements at a reduced power and smaller footprint than conventionaltwo-dimensional processes. 3D IC is just one of a host of 3D integrationschemes that exploit the z-direction to achieve electrical performancebenefits. They can be classified by their level of interconnecthierarchy at the global (package), intermediate (bond pad) and local(transistor) level. In general, 3D integration is a broad term thatincludes such technologies as 3D wafer-level packaging (3DWLP); 2.5D and3D interposer-based integration; 3D stacked ICs (3D-SICs), monolithic 3DICs; 3D heterogeneous integration; and 3D systems integration.

BRIEF SUMMARY

An embodiment of the invention may include a method, and resultingstructure, of forming a semiconductor structure. The method may includeforming a component hole from a first surface to a second surface of abase layer. The method may include placing an electrical component inthe component hole. The electrical component has a conductive structureon both ends of the electrical component. The electrical component issubstantially parallel to the first surface. The method may includeforming a laminate layer on the first surface of the base layer, thesecond surface of the base layer, and between the base layer and theelectrical component. The method may include creating a pair of viaholes, where the pair of holes align with the conductive structures onboth ends of the electrical component. The method may include forming aconductive via in the pair of via holes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a cross sectional view of a base layer after theformation of holes through the base layer, according to an exampleembodiment;

FIG. 2 depicts a cross sectional view of placement of a capacitor in theholes in the base layer, according to an example embodiment;

FIG. 3 depicts a cross sectional view of formation of a laminate layerand conductive layer, according to an example embodiment;

FIG. 4 depicts a cross sectional view of creating a conductive patternin the conductive layer, according to an example embodiment;

FIG. 5 depicts a cross sectional view of formation of via holes throughthe conductive pattern, base layer, and laminate layer, according to anexample embodiment;

FIG. 6 depicts a cross sectional view of creating conductive vias in thevia holes, according to an example embodiment;

FIG. 7 depicts a cross sectional view of joining a interposer to a die,according to an example embodiment; and

FIG. 8 depicts a cross sectional view of joining the interposer to asubstrate, according to an example embodiment.

Elements of the figures are not necessarily to scale and are notintended to portray specific parameters of the invention. For clarityand ease of illustration, dimensions of elements may be exaggerated. Thedetailed description should be consulted for accurate dimensions. Thedrawings are intended to depict only typical embodiments of theinvention, and therefore should not be considered as limiting the scopeof the invention. In the drawings, like numbering represents likeelements.

DETAILED DESCRIPTION

Exemplary embodiments now will be described more fully herein withreference to the accompanying drawings, in which exemplary embodimentsare shown. This disclosure may, however, be embodied in many differentforms and should not be construed as limited to the exemplaryembodiments set forth herein. Rather, these exemplary embodiments areprovided so that this disclosure will be thorough and complete and willconvey the scope of this disclosure to those skilled in the art. In thedescription, details of well-known features and techniques may beomitted to avoid unnecessarily obscuring the presented embodiments.

For purposes of the description hereinafter, terms such as “upper”,“lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, andderivatives thereof shall relate to the disclosed structures andmethods, as oriented in the drawing figures. Terms such as “above”,“overlying”, “atop”, “on top”, “positioned on” or “positioned atop” meanthat a first element, such as a first structure, is present on a secondelement, such as a second structure, wherein intervening elements, suchas an interface structure may be present between the first element andthe second element. The term “direct contact” means that a firstelement, such as a first structure, and a second element, such as asecond structure, are connected without any intermediary conducting,insulating or semiconductor layers at the interface of the two elements.The term substantially, or substantially similar, refer to instances inwhich the difference in length, height, or orientation convey nopractical difference between the definite recitation (e.g. the phrasesans the substantially similar term), and the substantially similarvariations. In one embodiment, substantial (and its derivatives) denotea difference by a generally accepted engineering or manufacturingtolerance for similar devices, up to, for example, 10% deviation invalue or 5° deviation in angle.

In the interest of not obscuring the presentation of embodiments of thepresent invention, in the following detailed description, someprocessing steps or operations that are known in the art may have beencombined together for presentation and for illustration purposes and insome instances, may have not been described in detail. In otherinstances, some processing steps or operations that are known in the artmay not be described at all. It should be understood that the followingdescription is rather focused on the distinctive features or elements ofvarious embodiments of the present invention.2.5 and 3D technologies areone mechanism of increasing chip performance. In such technologies, thethickness of the die is a contributing factor in performance. Thus,removing unnecessary structures in the die, and specifically the wiringof the die, can lead to a thinner die and increased performance.Structures such as deep trench capacitors, which serve to dampen powerfluctuations, may add to unnecessary thickness of the die, and mayaccomplish the same goals when placed in other places in amicroelectronics package.

Referring to FIG. 1, through holes 105 may be created in the base layer100. The base layer 100 may be a dielectric material, an organicmaterial or silicon. Non-limiting examples of the dielectric materialinclude, for example, epoxy, polyphenylether, polyphenyloxide, oxides,nitrides, oxynitrides of silicon, and combinations thereof. Oxides,nitrides and oxynitrides of other elements are also envisioned. Thematerial in the base layer 100 may be selected, or tuned, so thecoefficient of thermal expansion (CTE) of the material matches, or issufficiently similar, to the CTE of a substrate or die that may besubsequently attached. In addition, the base layer 100 may includecrystalline or non-crystalline dielectric material. In one embodiment,the base layer 100 may have a thickness, in some embodiments, rangingfrom about 400 μm to about 800 μm.

The through holes 105 may be created using mechanical, chemical or lasertechniques. The through holes 105 may be spaced such that they alignwith the placement of vias in subsequent steps. In an embodiment, thealignment may be between power and ground vias, and for processors maybe concentrated in the center of the interposer. In one embodiment, amechanical punch or drill may be used to create the through hole 105,starting on one surface of the base layer 100, and extending to theopposite surface of the base layer 100. Additional embodiments may usetechniques such as laser ablation, or patterning and etching away theunpatterned portions of the base layer 100. Through holes 105 should bebig enough to support the placement of any desired electricalcomponents, such as a capacitor, resistor or inductor. Further, throughholes 105 may have a width from about 100 to about 1000 μm.

Referring to FIG. 2, a capacitor 110 may be placed in the through hole105. The capacitor includes a conductive structure 112 located on eachside of a dielectric layer 115. The capacitor 110 may be oriented suchthat the conductive structure 112 and dielectric layer 115 are parallel,or substantially parallel, to the through hole 105, and perpendicular tothe surface of base layer 100. The conductive structure 112 may be madeof any conductive material such as, for example, copper, aluminum,tungsten, or any other suitable material. The dielectric layer 115 maybe made of any suitable dielectric material such as, for example, epoxy,polyphenylether, polyphenyloxide, and oxides, nitrides or oxynitrides ofsilicon. Further, while capacitor 110 is depicted as having 2 conductivestructures 112 separated by a dielectric layer 115, it should be notedthat the depiction is for simplicity, and other capacitor geometries arecontemplated. For example, multi-layered capacitors (such as multi-layerceramic capacitors) and decoupling capacitors may be used. Further, itshould be noted that capacitor 110 may instead be a resistor orinductor, depending on system requirements.

Referring to FIG. 3, a laminate layer 120 may be deposited on both sidesof the base layer 100, and may encase the capacitor 110. Subsequently, aconductive layer 130 may be formed on the laminate layer 120. Thelaminate layer 120 may be made of any suitable organic material such as,for example, an epoxy laminate. The laminate layer 120 may be depositedusing any number of techniques such as, for example, spin coating toB-stage adhesive lamination. The conductive layer 130 may be made of anyconductive material such as, for example, copper, aluminum, tungsten, orany other suitable material. The conductive layer 130 may be depositedusing any number of techniques such as, for example, electroplating.

Referring to FIG. 4, conductive layer 130 is patterned and etched,forming conductive pattern 133. The pattern applied, and thus created asconductive pattern 133, may be as conductive pads or a redistributionlayer (RDL), which may aid in subsequent bonding or electricaldistribution. In one embodiment, a photolithographic pattern may beapplied to the surface of the conductive layer 130, and an anisotropicprocess, such as, for example, reactive ion etching (RIE) or plasmaetching, may be used to remove the unpatterned material, leavingconductive pattern 133. In another embodiment, laser ablation may beused to remove unwanted portions of the conductive layer 130, leavingconductive pattern 133.

Referring to FIG. 5, via holes 107 may be formed through the base layer100, the laminate layer 120 and the conductive pattern 133. The viaholes may be patterned in such a way that they correspond to electricalconnections on a die and substrate that will subsequently be attached.In one embodiment, the via holes 107 may be formed using aphotolithography process followed by an anisotropic etching process suchas reactive ion etching (RIE) or plasma etching. In another embodiment,the via holes 107 may be formed using laser ablation techniques.

Referring to FIG. 6, conductive vias 140 may be formed, and aninterposer 10 is created. Formation of the conductive vias 140 may beperformed using a plating process for filling via holes 107. Theconductive vias 140 may be formed from a metallic material such as, forexample, copper, aluminum, tungsten, or any other suitable material.

Referring to FIG. 7, interposer 10 may be connected to a die 200, suchas, for example, a processor, memory, etc. In one embodiment, the die200 may be connected to the interposer 10 using electrical connection210. Electrical connection 210 may be any material capable of forming anelectrical and mechanical connection between the die 200 and interposer10. In one example embodiment, electrical connection 210 may be a seriesof solder bumps that have undergone a reflow process (e.g. melting andfusing), joining the die 200 and interposer 10. This may be performed bydepositing the solder bumps above the conductive via 140, and usingthermal compression to allow for reflow of the solder bumps, in order tocreate an electromechanical connection. In such embodiments, theconductive vias 140 (and thus solder bumps) would be aligned withconductive wiring (not shown) located in the substrate 300. In anexample embodiment, electrical connection 210 may be the only physicalconnection between the die 200 and interposer 10 (i.e. no underfill isused). This may be accomplished in instances where the CTE for the die200 and interposer 10 are the same, or sufficiently similar such thatthe unwanted properties would not arise (e.g. stress causing warpage orfracture from differences in CTE). In such embodiments, removal of die200 without damage to either the die 200, or interposer 10 may beaccomplished.

Referring to FIG. 8, interposer 10 may be connected to a substrate 300,such as a package substrate. The substrate 300 may be an additional die(similar to die 200), or a package substrate. This may be performed bydepositing the solder bumps above the conductive via 140, and usingthermal compression to allow for reflow of the solder bumps in order tocreate an electromechanical connection. In such embodiments, theconductive vias 140 (and thus solder bumps) would be aligned withconductive wiring (not shown) located in the substrate 300. Inembodiments where the substrate 300 is a package substrate with a CTEthat does not match the interposer 10, a curable non-conductivepolymeric underfill material is dispensed onto the substrate 300adjacent to the chip and is drawn into the gap by capillary action,forming underfill layer 350. The underfill material providesenvironmental protection, and mechanically locks together the interposer10 and the die 200 so that differences in thermal expansion of the twomaterials do not break the solder fused connection 330. The underfillmaterial may comprise one or more polymerizable monomers, polyurethaneprepolymers, constituents of block copolymers, and constituents ofradial copolymers, initiators, catalysts, cross-linking agents,stabilizers, and the like. Such materials polymeric materials containmolecules that are chained or cross-linked to form a strong bondingmaterial as they are cured and hardened.

Following the connection, interposer 10 may allow current to flowbetween the substrate 300 and die 200. The interposer 10 may beconnected to the front side of the die 200, or alternatively may beattached to the back side of the die 200 and form electrical connectionsthrough TSVs located throughout the die 200. The introduction ofcapacitor 110 may allow for dampening of power noise (e.g. fluctuationsin voltage or amperage), by attenuating the flow of charge into, or outof, the die 200. Additionally, by bringing the capacitor 110 closer tothe die, loop inductance for the system is reduced, which improves thedampening of the power noise. Further, by matching the CTE of the die200 and interposer 10, underfill is not required to secure the joinder,and thus the separation of the die 200 and interposer 10 can beperformed with little or no damage to either.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiment, the practical application or technicalimprovement over technologies found in the marketplace, or to enableother of ordinary skill in the art to understand the embodimentsdisclosed herein. It is therefore intended that the present inventionnot be limited to the exact forms and details described and illustratedbut fall within the scope of the appended claims.

What is claimed is:
 1. A semiconductor structure comprising: a baselayer with a first surface and a second surface; a capacitor located inthe base layer, wherein the capacitor is substantially parallel to thefirst surface, and wherein the capacitor comprises an electricalconnection on each end of the capacitor; a laminate layer located on thefirst surface and the second surface of the base layer, and between thebase layer and the capacitor; and a conductive via extending from eachelectrical connection to the first surface and the second surface. 2.The structure of claim 1, further comprising a semiconductor dieelectrically connected to the conductive via extending to the firstsurface.
 3. The structure of claim 2, wherein the coefficient of thermalexpansion of the base layer and the semiconductor die is substantiallysimilar.
 4. The structure of claim 2, further comprising a packagingsubstrate electrically connected to the conductive via extending to thesecond surface.
 5. The structure of claim 4, further comprising anunderfill layer between the second surface of the base layer and thepackaging substrate.
 6. The structure of claim 1, wherein the base layercomprises an epoxy polymer.